LED light sources are applied in more and more situations for its advantages of long lifespan, high lighting efficiency, environmental protection and the like. Since the lifespan of the LED light source is more than 50,000 hours, the main reason for malfunctions of an LED lamp is that a constant current driver for the LED light source becomes invalid. Among the reasons for malfunction of the constant current driver for the LED light source, invalidation of individual semiconductor devices is the most outstanding reason, and the main reason for the invalidation of individual semiconductor devices is that: the LED light source becomes quite hot by itself, and since the constant current driver for the LED light source is generally placed inside the lamp and close to the LED light source, operating characteristics of a semiconductor device are greatly affected by the high-temperature working environment.
In the prior art, one LED lamp is generally equipped with one constant current driver, and the reliability is low. When an LED lamp is turned off due to malfunctions of the constant current driver for the LED light source, there is a need to replace the driver manually, resulting in high maintenance cost, and particularly in some application scenarios. For example, once an LED lamp applied to a tunnel or a road fails and needs to be repaired, it is necessary to block the driveway, bringing inconvenience to the public traffic; further, there is a certain hidden danger in the repairing. Overall, the constant current driver for the LED light source in the prior art has low reliability, resulting in high cost for repairing it.